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An Optimized Hemagglutination Inhibition HI Assay to Quantify Influenza-specific Antibody Titers
Published on: December 1, 2017
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Human serum activities against Hemophilus influenzae, type b.
The Journal of Clinical Investigation
|January 1, 1972
Summary
Humoral immunity against Hemophilus influenzae type b involves antibodies targeting both its capsule and somatic antigens. While anticapsular antibodies offer uniform protection, antisomatic antibodies show variable effectiveness against different strains.
Area of Science:
- Immunology
- Microbiology
- Bacteriology
Background:
- Humoral immunity is crucial for combating bacterial infections.
- Hemophilus influenzae type b (Hib) poses a significant health risk, particularly to young children.
- Understanding immune responses to Hib is vital for developing effective vaccines and treatments.
Purpose of the Study:
- To investigate the components of humoral immunity against Hemophilus influenzae type b in normal adult humans.
- To assess the roles of anticapsular and antisomatic antibodies in antibacterial activity.
Main Methods:
- Assays for serum bactericidal and opsonizing activities against Hib.
- Passive hemagglutinating activity assays using erythrocytes sensitized with polyribophosphate (Hib's capsular antigen).
- Analysis of 114 human adult sera.
Main Results:
- Hemagglutinating activity, indicating anticapsular antibodies, was detected in approximately 60% of sera.
- All tested sera exhibited bactericidal and opsonizing activities, though levels varied.
- Antibacterial activities were attributed to both anticapsular and antisomatic antibodies.
- Hib strains showed differential susceptibility to antisomatic antibodies but uniform sensitivity to anticapsular antibodies.
Conclusions:
- Normal adult humans possess humoral immunity against Hemophilus influenzae type b.
- Both anticapsular and antisomatic antibodies contribute to antibacterial defense.
- Anticapsular antibodies provide a consistent level of protection, while antisomatic antibodies offer strain-specific immunity.
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